The purpose of this project is to improve our understanding of ways in which drugs may alter centrally mediated neurotransmission and to develop better pharmacotherapies for neurological disorders. Topics currently under investigaton include: 1) effects of dopamine agonists on function of nigro-striatal dopaminergic systems; 2) factors regulating glutamic acid decarboxylase activity; 3) effects of drugs on gamma-aminobutyric acid (GABA) synthesis; and 4) role of GABA-containing neurons in the regulation of dopaminergic function. BIBLIOGRAPHIC REFERENCES: Walters, J.R. and Chase, T.N.: GABA Systems and extrapyramidal function. In Fields, W.S. (ed.): Basic and Clinical Aspects of Neurotransmitter Function. Miami, Symposia Specialists, 1977, pp. 193-211. Walters, J.R. and Roth, R.H.: Gamma-hydroxybutrate: Considerations of Endogencus Role and Therapeutic Potential. In Usdin, E., Barcus, J. and Hamburg, D. (Eds.): Neurotransmitters and Hypotheses of Neurological Disorders. New York, Oxford Press, 1977, pp. 403-415.